Process for the preparation of oximes

ABSTRACT

A process for synthesizing an oxime by reacting an organic carbonyl compound with a hydroxylammonium sulfate and ammonium hydrogen sulfate in the presence of ammonium dihydrogen phosphate whereby an aqueous solution of phosphoric acid and ammonium sulfate is obtained after separating the oxime product therefrom. The phosphoric acid, ammonium sulfate solution can be used in processing rock phosphate with the aid of nitric acid to product a fertilizer composition having a N to P2O5 ratio of approximately 1:1.

United States Patent [191 Elmendorp et a1.

[4 1 Apr. 24, 1973 PROCESS FOR THE PREPARATION OF OXIMES Inventors: Jan Elmendorp, Brunssum; Abraham H. De Rooij, Geleen, both of Netherlands Assignee: Stamicarbon, N.V., Heerlen,

Netherlands Filed: June 15, 1971 Appl. No.:' 153,187

Foreign Application Priority Data June 17, 1970 Netherlands ..7008838 US. Cl. ..71/34, 71/35, 71/37, 260/566 A, 423/310, 423/313 Int. Cl. ..C05b 11/04 Field of Search ..260/566 A; 71/37, 71/39, 41, 3436; 423/310, 313

References Cited UNITED STATES PATENTS 8/1971 Slot et a1. ..71/37 3,667,904 6/1972 Roche et a1. ..71/39 3,342,580 9/1967 Rooij... ..71/39 3,641,150 2/1972 Rooij .....260/566 A 3,335,183 8/1967 Rooij ..260/566 A FOREIGN PATENTS OR APPLICATIONS 1,496,435 9/1967 France ..260/566 A 1,073,248 6/1967 Great Britain ..260/566 A Primary E.raminerReuben Friedman Assistant ExaminerRichard Barnes Attorney-Cushman, Darby & Cushman [57] ABSTRACT 4 Claims, 2 Drawing Figures Patented April 24, 1973 3,729,304

2 Sheets-Sheet 1 Patented April 24, 1973 3,729,304

2 Sheets-Sheet 2 C D i 5 I FIGQ 1 Pii'o'cEss Fo'R' THE PREPAizATIoN F OXIMES The present invention relates to the preparation of oxiines from the reaction of an organic compound containing a carbonyl group with a hydroxylarnine solution wherein the hydroxylari'iine solution is obtained by reduction of a solution coritaining nitrite and bisulfite with sulfur dioitide followed by hydrolysis of the hydroxylamine disulfohate formed; In such process, an aqueous solution of ammonium nitrite and ammonium bisulfite is reacted with so forming ammonium salt or the hydioxylainihe disu'ifrhie acid according to the following reaction mechanism:

NH NO NH HSOg so; H'O'N('S'O',,NH

Sulfuric acid is then dited ie the i'esuliifig solution of the ammonium salt of hydroigylatiiin'e disulfoni'c acid to adjust the solution to a of zippi oiiirn ately 2 whereu pen the seiutiee is heated aridthe hydroxylainine disulfonic ammonium salt is hydroli'zed to the hydroxyl arrirnonium ammoniurii sulfate and ei'iiin'eiiiiiin' hydrogen sulfate acco rding to the renewing quatioiis:

Niki-i569 and l'lONl'iSdhiili H 6 HUNH Nl-iiSOg. The ammonium hydrogen sulfate is normally heht'ril i'z ed with N'i-ig f0 resulting aiiiihoiiiuin sulfa t' soluti'oh is used in the A which the hydroxyl airi ga'riic 'coinpoiihd coritaihiri aihrnoiiiiiiii sulfate as a by-preauei using relative ex sive NHg, is commercially uiiattiac tive because ammonium sii ate; which is used as 'a nitrogenous f erti liier, is commercially overprodu ced and as a result of little cohirneicial value. It would e advahtag'eous to" iecovei the a'riiino'riitirn hydroe'h sulfate itself rather than convei't it to ammonium sulfate. The ahirnoniuiii hydiege'ii sulfate co iild then further he processed, utilizing the sul furic eeid eeetem thereof in the decomposition of rock phosphate. it has been proposed to carry out the preperaiieh of exinie in a moderately aeid reaction mii'tture A which contains such a quantity of ammohiuin' sulfate that the buffering actioh 'ef the combination ammonium Slllfiitiziiilhlditium hyciidgen sulfate iii the reaction mixture along with the hydroxyl aihrhohium-amrhonitlin s'iiii'a e during the preparation of the oi i irne, results in a pH suitable for the preparation of the ox imie; and whereupon, the oxime caii be separated from the acid solution with the remaining solution containing I free ammonium hydrogen sulfate being discharged. A major disadvantage associated with the ieco'v'ery of ammonium hydrogen sulfate in this manner is that it contains dissolved ammonium sulfate. The ammonium hydrogen 2t sulfate solution containing dissolved sulfate can he used in prparingfe'rtiliier ei'si'i'ifias it; I the decomposition of rock phos hate with mtfic acid iiii' i'eii' eva'i of calcium in the with at gy isui'ii; How'vi fertilizer compositions h'evii'ig rsi p' 'o weight retro 6'? :1 or higher depending on the aifio'urit 6f afi'if'r'iriiurh sulfate present in the aifiihdriiufii hydrogen sulfate s iition. It is, however; dsirahle s produce fi'tiiiiei' denipe'e'itiei'is having e lewe'i N p o weight ieiti such as lzl.

The pies-em invention pie-vide a time iei' iie ieiing' an oiiiine wherein the acid solutlori which is e' i'ziratedff'rtiiii the oxii'fii iii beiised dii ectly iii processing rock phosp aid of iiitii'c acid to ill jte'iy ieiivei a iiiiit'd fertiliiei eiii seeiii'eii havin a N to P 6 weight ie i i =1; iii the ieeese of the piee 'it inventioh, the re oxiine from the acid solution contaiiiiii hydroxl moniuih-arn'rhohiurn sulfate end ai'ii 'riohiiiiri hydro sulfate is c rolled to take place the present:

fr eieii q ieiiiiiy er i iiiiei ui dihydfogeh ii e i te that; at the end of the eiii efeiiiieiieii ti sa ofth ture is at Ieast OIS, measured at a tempora reaction ture of 6 c. At such a pH, iiie ieiaieiieii 6f QSpejrceiit and the conversion is even mote, coiiiplete at er pH values. A p y To achieve a pH of at least 0.5 in the reietioh product iiiii'iture at the end of the o iiiine' formation; a 30 I iex'iiiiei'ely ohe mole of Nl Ll-I 'P O musthe added to the fea c tioii inechanis'rii foi e'aeh mole of v h iii'e ea serrate which is iii'eeeiii. The tin ii rjo reacts with the aiiiriioniurn hydrogen siiliate foi iiiiiifi ftepho phoric acid and amrhohiuiii sulfate; The p'r dtie'ss of the present invention eaimsiieeg productioii oi oitimes by reacting a carbonyl c M cor ripoiind and an aqueous solution of hy r y aiii moniiii'riahirnoniuni sulfate and aifhmoiiiti iii hy'cli'og'eh sulfate eb eine'd B' eeiweitiii a solution of iiiiiii'i nitriteand ani'moniuin bisulfite to the ariiinoniuih a t of hydi'oxylarriin'e disulfonic acid by rediletioii with someuaw a by hydrolysis of ihe'amiiiei'iiiiihfsaii is a soluti'oh at hydroxylam'moniuin-animoniuin sill ammoiiiurii hydrogen sulfate. The oxirne synthesis reaction of the present invention is acconip k i (5 presence of ammonium dihydro'gen phosp ate. ammonium dihydr'ogen phosphate is added to the oxirhe synthesis feed in such quantity that the reaction product mixture has a pH; measured at 2 5 6; of at least 0.5. The oxime product is then see p from the remaining synthesis reaction ri iiittii'ewhliih comprises an aqueous solution containing phosphoiie acid and ammonium sulfate. T V The aqueous solution containing phosphoric acid and ammonium sulfate is then utiliied directly iri processing of rock phosphate with the aid of nitiic aeitl; The aqueous phosphoric acidand ainmoriiuni 'te solution is added to the decomposition mass obtained from treating phosphate rock with nitric a d; pon gypsum is precipitated and an a'rhr'n'oiiiiiiii hit r iite and free phosphoric acid solution em be i ate-3 therefrom. The phosphoric acid comporieiit is heuti'al iz'ed with ammonia forming ammonium diliyclio ii phosphate. A portion of the ammonium tiihy phosphate-ammoniuni nitrate solution is rciieul iteii to the oxime synthesis Zone to supply the requiied amount of ammonium dihydrogen phosphate to the oxime synthesis reaction. The remaining ammonium dihydrogen phosphate-dihydrogen phosphate solution is concentrated by evaporation and granulated to form a mixed fertilizer having a N to P weight ratio of approximately 1:].

The carbonyl compound used in the oxime synthesis can be an alicyclic ketone such as cyclohexanone, cyclopentanone, methycyclohexanone and cycloheptanone or aliphatic ketones having the formula 0 R-iL-R carbon atoms.

The several process steps of the present invention can be accomplished at atmospheric, subatmospheric or superatmospheric pressures.

The reduction of ammonium nitrite and ammonium bisulfite with S0 can be accomplished at temperatures of from about -7 C to about +4 C. After the reduction with S0 sulfuric acid is added to the reaction mixture to give a solution pH of approximately 2 and subsequently the reaction mixture is heated to a temperature of from about 105 C to about 110 C to accomplish the hydrolysis of the hydroxylamine disulfonic ammonium salt to hydroxylammonium-ammonium sulfate and ammonium hydrogen sulfate. The oximation reaction can be conducted at temperatures from about 75 C to about 80 C. Temperatures of the solutions in the various steps of the decomposition of the rock phosphate and precipitation of gypsum from the decomposition mass are not critical.

The present invention will be more fully described with reference to the drawings and the following description of the preferred embodiments.

In the drawings:

FIG. 1 is a graph showing the relation between the pH and molar ratio between the NH',H PO, and NH H- SO, in solutions containing about 55 percent by weight of water. The pH is plotted on the ordinate and the molar ratio of NH H PQ to NH,,HSO., on the abscissa.

FIG. 2 is a schematic diagram of one preferred embodiment of the process of the present invention.

As mentioned above, ammonium dihydrogen phosphate is added. to the oxime reaction medium in sufficient amounts that the pH of the reaction product solution from the oximation step has a pH of at least 0.5 measured at a temperature of 25 C. The relationship between the ratio of NH,H PO, and NI-I HSO, in solutions containing approximately 55 percent by weight water is shown in FIG. I. As can be seen, an equal number moles of NH H PO to moles of NH,HSO are required to produce a pH of 0.5. A molar excess of NH4H PO4 to NH4l-ISO4 produces a pH ofin excess of 0.5 and thus can be effectively used in the present invention.

One preferred mode of performing the process according to the invention, in which the aqueous solution of phosphoric acid and ammonium sulfate from the oximation process is utilized in the treating of rock phosphate with the aid of nitric acid, is shown schematically in FIG. 2. Referring now to FIG. 2, an acid solution of hydroxylammonium-ammonium sulfate and ammonium hydrogen sulfate is fed to mixing vessel A through line 26. Ammonium dihydrogen phosphate is fed to mixing vessel A through line 19. The mixture formed in mixing vessel A is introduced to the oximation reactor B by line 27. In addition, the ketone being utilized is fed to reactor B through line 1.

The oxime formed in reactor B is discharged through line 2, while the solution containing phosphoric acid and ammonium sulfate and which has been freed of oxime is introduced to a gypsum precipitation vessel D by line 3. A decomposition liquid obtained by treating rock phosphate with nitric acid in reactor C, is supplied to vessel D through line 6. Rock phosphate and nitric acid are supplied to reactor C by lines 4 and 5 respectively.

A gypsum slurry in aqueous phosphoric acid is formed in vessel D. A portion of the gypsum slurry is recirculated by lines 7 and 8 to decomposition reactor C with the remainder of the gypsum slurry flowing through line 9 to separation section E, of a liquid-solid separating device such as a filter or decanter, where the gypsum component is separated from the phosphoric acid mother liquor. The mother liquor is fed to neutralization vessel F where it is reacted with Nl-I fed to vessel F through line 15. The ammonium dihydrogen phosphate formed by the reaction in vessel F is fed to evaporator G, through line 16 and concentrated in evaporator G,. A portion of the concentrated ammonium dihydrogen phosphate solution from evaporator G, is recirculated to mixing vessel A through lines 18 and 19. The remainder of the ammonium dihydrogen phosphate solution from the evaporator G, is forwarded to evaporator G, where it is further evaporated to a melt of mixed fertilizer composition having an N to P 0 weight ratio of approximately 1:1. This melt is granulated in a known manner. Alternatively, a potassium salt can be added to the melt prior to granulation.

The water vapor from evaporators G, and G is removed in lines 17, 22, and 23. A portion of the water vapor is removed from the system through line 24. The remainder of the water vapor is condensed and forwarded to washing section E of the liquid-solid separa' tor wherein the gypsum from separating device E, is washed. The washed gypsum is discharged by line 12 and the wash water and dissolved mother liquor is added to the phosphoric acid mother liquor from separator E, by line 13.

The schematic diagram of FIG. 2 shows a preferred mode of performing the process of the present invention, however, the present invention is not limited thereto. The process shown in FIG. 2 can be modified in various ways within the scope of the present invention. For instance, mixing vessel A can be deleted in which case, the acid solution of hydroxylammoniumammonium sulfate as well as the solution containing ammonium dihydrogen phosphate are introduced into the oximation reactor B. Further, the decomposition reactor C and the gypsum precipitation vessel D can be incorporated into one reactor in which the decomposition of rock phosphate and the precipitation of gypsum take place simultaneously. The use of two vessels wherein the rock phosphate is decomposed in the first and the gypsum precipitated in the second has the advantage of higher decomposition of rock phosphate efficiency as encapsulation of rock phosphate by precipitating gypsum is avoided.

The process shown in FIG. 2 can further be modified by crystallizing Nl-LH PQ, from the solution exiting from evaporator G and recirculating the crystals of NH4H PO to mixing vessel A. This involves the added cost of a crystallizer, but on the other hand, process flows of a higher concentration are obtained.

EXAMPLE Using the apparatus shown in FIG. 2, 100 moles of cyclohexanone was supplied to oximation reactor B through line 1, and 100 moles of hydroxylamine in the form of an acid solution of hydroxylammonium sulfate was fed to reactor B through lines 26 and 27. The oxime product comprising 100 moles of cyclohexanone oxime and 20 moles of water were withdrawn from the reactor B through line 2.

The decomposition reactor C was supplied through line 4 with rock phosphate containing 225 moles of CaO and 61 moles P An amount of 55 percent by weight solution of l-lNO equivalent to 230 moles HNO was added to reactor C through line 5. The slurry of decomposed rock phosphate was forwarded from reactor C to gypsum precipitator D. Themother liquor from the oximation reactor B containing 220 moles H PO 457 moles NH NO 225 moles (NI-1.0 50 and 2,580 moles of water was added to the decomposed rock phosphate slurry in precipitator D.-

A slurry containing 342 moles H PO 1,925 moles NH NO 617 moles NH H PO 631 moles CaSO and 9,194 moles of water was discharged from precipitator D of which a portion comprising 220 moles H PO 1,238 moles NH NO 397 moles NH H PO 406 moles CaSO and 5,914 moles of water was recirculated to the decomposition reactor C to process further rock phosphate. The remaining solution from precipitator D comprising 122 moles H PO 687 moles NH No 220 moles NH H PO 225 moles CaSO and 3,280 moles of water was introduced to separator E by line 9. The gypsum component comprising 22 moles H PO 124 moles NH NO 40 moles NH H PO 225 moles CaSO, and 1,170 moles of water was separated from the mother liquor and discharged through line 11 to washing apparatus E The mother liquor from separator E comprising 100 moles'l-l PO 563 moles NH NO 180 moles NH H PO and 2,320 moles of water was forwarded by line and 14 to neutralization vessel F. Wash water from washing apparatus E comprising 22 moles H PO 124 moles NH NO 40 moles NHJ-I PQ, and 1,500 moles of water was added to the mother liquor fed to neutralizer F through line 13. Ammonia in an amount of 122 moles was added to neutralizer F by line 15.

The solution discharged from the neutralization reactor F contained 687 moles NH NO 342 moles NH4H PO and 3,820 moles of water was forwarded through line 16 to evaporator G The solution was concentrated in evaporator G with 1,800 moles of water vapor removed through line 17. The concentrated solution comprising 687 moles NH NO 342 moles N1-l4H2PO and 2,020 moles of water was withdrawn from evaporator G through line 18. A portion of this concentrated solution comprising 442 moles NH NO 220 moles Nl-I.,H PO and 1,300 moles of water was.

prising 245 moles NH NO 122 moles NH H PO4 and 720 moles of water was forwarded by line 20 to evaporator G This solution was evaporated and 702 moles of water vapor removed through line 22. The concentrated solution comprising 245 moles NH NO 122 moles NH H PO and 18 moles of water was discharged from evaporator G through line 21. The composition discharged from evaporator G was granulated into a solid fertilizer composition having 25 percent by weight N and 25 percent by weight P 0 The water vapor from evaporators G and G amounting to 3,204 moles of water was condensed, of which 1,710 moles was recirculated to apparatus E to be used in washing the gypsum precipitate. The remaining water amounting to 792 moles was discharged from the system through line 24.

The crystallization temperature of the composition withdrawn from evaporator G was 120 C and the crystallization temperature of the feed composition to reactor B was C.

What is claimed is:

1. A process for the preparation of oximes by reaction of a carbonyl compound and an aqueous solution of hydroxylammonium sulfate and ammonium hydrogen sulfate, said process being characterized in that the oxime-forming reaction takes place in the presence of ammonium dihydrogen phosphate in such a quantity that the pH of the reaction mixture at the end of the oxime formation is at least 0.5, measured at 25 C, whereupon the oxime product is separated from the aqueous phase reaction mixture which contains phosphoric acid and ammonium sulfate, adding said phosphoric acid and ammonium sulfate to the decomposition product obtained from treating rock phosphate with nitric acid, whereupon a suspension of gypsum, ammonium nitrate and free phosphoric acid is produced, said gypsum is removed from the ammonium nitrate-phosphoric acid solution and the phosphoric acid content thereof neutralized with ammonia to ammonium dihydrogen phosphate, a portion of said ammonium dihydrogen phosphate is recirculated to the oximation zone, with the remaining portion of the ammoniated solution being concentrated by evaporation and granulated to a mixed fertilizer composition having an N-P O weight ratio of approximately 1:1.

2. A process as claimed in claim 1 wherein the ammonium dihydrogen phosphate is present in a molar amount at least equivalent to the amount of ammonium hydrogen sulfate.

3. A process according to claim 1, characterized in that solid ammonium dihydrogen phosphate is crystallized from the solution containing ammonium nitrate and ammonium dihydrogen phosphate and the quantity of crystals formed is recirculated to the oximation zone.

4. A process according to claim 1 wherein a portion of the ammoniated solution is recirculated to the oximation zone. 

2. A process as claimed in claim 1 wherein the ammonium dihydrogen phosphate is present in a molar amount at least equivalent to the amount of ammonium hydrogen sulfate.
 3. A process according to claim 1, characterized in that solid ammonium dihydrogen phosphate is crystallized from the solution containing ammonium nitrate and ammonium dihydrogen phosphate and the quantity of crystals formed is recirculated to the oximation zone.
 4. A process according to claim 1 wherein a portion of the ammoniated solution is recirculated to the oximation zone. 